A silver halide photographic material, usually comprises a silver halide emulsion layer and an anticurl backing layer provided on a support.
The silver halide emulsion layer comprises silver halide grains dispersed in a hydrophilic binder such as gelatin. The emulsion layer absorbs the moisture because the hydrophilic binder is hygroscopic. Therefore, the photographic material tends to be curled according to the change of the humidity. The curled photographic material causes a jam while conveying the material in an automatic processing machine.
An anticurl (non-curling) backing layer is usually provided on the reverse side of the support to prevent the photographic material from curling. The anticurl backing layer contains a hydrophilic binder. The hygroscopic property of the anticurl backing layer is analogous to that of the emulsion layers. The curling force caused by the emulsion layer is balanced with the reverse curling force caused by the anticurl backing layer.
By the way, a recent silver halide photography requires rapid processes, namely a rapid development process, a rapid fixing process, a rapid washing process and a rapid drying process. The requirement of speedup is severe particularly in printing technical fields. The rapid process is also required to reduce the amounts of the waste processing solutions. Therefore, the silver halide photographic material has recently been improved to shorten the processing time.
The above-mentioned anticurl backing layer causes problems in the rapid processes of the photographic material. For example, the hydrophilic binder of the anticurl backing layer absorbs water contained in the processing solutions. A relatively long time is required to dry the layer absorbing water. Further, the amount of a replenisher should be increased to compensate the absorbed water.
Furthermore, even if the anticurl backing layer is removed from the photographic material, the problem remains. The support in place of the anticurl backing layer absorbs water in the processing solutions. The support absorbing water loses the dimensional stability.
European Patent Publication No. 107378A1, Japanese Patent Provisional Publication Nos. 56(1981)-17352, 59(1984)-218438, 5(1993)-127282(corresponding to U.S. Pat. No. 5,219,718 and European Patent Publication No. 514903A1) and 5(1993)-127306 propose a silver halide photographic material having a hydrophobic backing layer provided on the anticurl backing layer or the support to solve the above-mentioned problems caused by water contained in the processing solutions. The hydrophobic backing layer contains a hydrophobic polymer, which has a function of shielding the anticurl backing layer or the support from the processing solutions. The layer disclosed in European Patent Publication No. 107378A1, Japanese Patent Provisional Publication Nos. 56(1981)-17352 and 59(1984)-218438 are formed by fusing core/shell polymer particles together.